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Immobilization of alliinase and its application:
Flow-injection enzymatic analysis for alliin
Jianqin Zhou
School of Pharmaceutical Sciences, Medical College, Soochow
University, Suzhou 215123, P.R., China. E-mail:
zkzhu@ustc.edu. Tel.:
+86 512 65880025. Fax: +86 512 65880031.
Accepted 26 February, 2009 |
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Alliinase was immobilized on chitosan microspheres by means
of glutaraldehyde, and a flow-injection enzymatic analytical
system was developed for determination of
alliin
based on the immobilized alliinase and an ammonia gas
electrode.
The
factors affecting the activity of the immobilized enzyme,
such as glutaraldehyde concentration,
cross-linking time and the amount of alliinase, were
investigated. Results showed that the maximum of enzyme
activity could be obtained at
glutaraldehyde concentration of 4%,
cross-linking
time of 2 h and
the
amount of alliinase
20.2 u.
The
properties of the immobilized alliinase were also studied in
detail. For the immobilized alliinase, the highest activity
was allowed at pH of 7.0 and temperature at 35°C.
Besides, the immobilized enzyme showed good thermal and pH
stabilities. The
flow-injection
enzymatic analytical system
based on the immobilized alliinase and an ammonia gas
electrode provided linearity in the 1
× 10-5 to 1
× 10-3
mol/L alliin concentration range and exhibited good
repeatability and operational stability.
Key words:
Alliinase, immobilization, enzyme properties, flow-injection
analysis. |
